Devices for manipulating fluids on the microscale have been developed to store, hold, and manipulate small amounts of fluids and have been applied to the detection of analytes in sample fluids. For example, capillary electrophoresis, generally involving the separation of charged species in solution, can be advantageously performed in a microchannel—see for example WO 96/04547, incorporated herein by reference. Electrokinetic and electroosmotic forces have been used to manipulate fluids in microfluidic devices, see WO 96/04547 for example. Manipulating fluids and performing capillary electrophoresis in microfluidic devices promises advantages of small size, high throughput, low sample volumes, and cost.
However, the performance offered by present microfluidic devices is limited by the interfaces between the microfluidic device and the macroscopic world. Connecting detection units including light sources and other detectors, power sources necessary for any actuators or detectors, and macroscopic amounts of reagent fluid and/or sample fluid to present microfluidic devices is cumbersome—often requiring a lengthy process of trial and error or limiting the use of the microfluidic device to one reagent source, or to one detector, or to a single configuration.
Further, although microfluidic devices themselves can have a small form factor, once they are connected to the systems required for their operation—including voltage sources, macroscopic fluid sources, and detectors—the entire system can become too large to be portable.
There is therefore a need for a system that manipulates fluid to detect target analytes on the microscale while providing flexibility to use any of a variety of desired macroscopic parts—including, for example, reagent reservoirs, voltage systems, detectors, and the like. Such a system would desirably be portable.